<b>Tree Care Guide:</b> Common tree care questions

SchafferLandscapers don’t have to necessarily offer tree and shrub care to answer homeowners’ questions about what’s happening with their ornamentals.

“As long as you can communicate with your customer… you’re going to have client retention,” says Elliott Schaffer, certified arborist and founder of Environmental Horticultural Services in Dublin, Ohio. “As long as you can help solve their problems... You want to be preemptive and notice these things and tell the customer.”
 
Plants encounter two problems: biotic – caused by living organisms such as fungus, nematodes, insects, bacteria or mites; and abiotic – caused by physical or chemical damage, temperature and moisture extremes and planting.

For example, a client with eaten hosta, a browse line on evergreens and bark damage from rubbing means you have deer, which is a biotic problem.

On the other hand, abiotic  problems are sometimes harder to diagnose and remedy. Schaffer gave the following examples and possible solutions.
 
Soil Compaction
Contractors need to recognize the visual cues that are being presented to them. For example, everything a home builder can’t – or doesn’t want to – haul away, he’ll bury. So, if you find a 4-foot-wide by 7-foot-long rectangular spot of dead turf, it’s most likely not a disease. It’s probably just a burried door. 

But problems with trees or shrubs from buried cast-offs are harder to pinpoint because the damage doesn’t show up for a year or two after planting. By that time, homeowners aren’t thinking about when the house was built.

Similarly, roots growing close to the surface are an indication of soil compaction. When they see roots above grade it means the soil is too compacted for the roots to grow underground. Instead, the roots grow up to get the oxygen they need. “Roots, whether it’s turf or ornamentals, need oxygen,” Schaffer says Contractors can trim up to one-third of the roots off a healthy tree. But if you can’t cut the roots, consider mulching the base of the tree.

Poor Drainage
One symptom of wet mulch is vomitora fungus – so named because it resembles throw-up. It’s always present in hardwood mulch, but you’ll see it flower when the mulch is too moist. “It doesn’t hurt humans, but it is an indicator that this mulch is too wet. Either thin the mulch or change the irrigation,” Schaffer says.
    
He recommends contractors carry a soil probe to assess the moisture content underneath plants. 
 
Heat Damage or Scorch
This is seen most often on the margins of leaves and needles, where water has to travel the farthest, and on plants with immature root systems. Plants can sustain heat damage from the hot hoods, motor vehicle exhaust or even asphalt applied in the summer.
 
If the tips of conifer needles are green, then the plant is getting enough water. And if the internal needles are brown, then the tree is just dropping some leaves that it doesn’t need anymore, Schaffer says.

Freezing Damage
Evergreen trees and shrubs express winter freeze damage around the same time as a homeowner’s first or second lawn care application. The leaves on deciduous plants will turn black or tree bark will burst. 
 
Schaffer recommends technicians keep their eyes open while driving to each account.
 
“On your way to the property, look around,” he says. “Is it just your client or the whole neighborhood?” 
 
Communicate to homeowners who have relocated from a vastly different hardiness zones that they can’t expect the same results from the same plants. “Make sure the plants you have are right for the market,” Schaffer says. “The plants you grew in Buffalo don’t grow here in Tuscaloosa.” 
 
Herbicide Damage
As chemicals become more advanced, Schaffer is seeing less tree and ornamental damage from herbicides applied to turf.
    
However, if a homeowner believes your latest application killed his burning bush, look around for weeds. It’s easier to kill weeds than it is to kill established shrubs and trees. If there are still weeds around a damaged plant, then the problem wasn’t the chemical you applied last week. Be aware that aphids, thrips and freezing temperatures can cause damage with similar looking symptoms.
 
To learn more about specific tree care problems, lists of deer-resistant plants and to find materials suitable for use as customer handouts, check out the extension offices at land grant universities.

Also, you can find a clearinghouse for extension sites at http://extension.unh.edu/cesites.htm. 
 
The author is managing editor of Lawn & Landscape. E-mail him at cbowen@gie.net.